"I hope not scoring a goal doesn't come back to bite us," the United boss said after the 0-0 first leg match.
"However, I think we deserved to win. We played very well. They gave us 15-20 minutes of pressure as we expected in the second-half.
"But we showed good composure and maturity. The players enjoyed playing in that kind of atmosphere.
"There's obviously disappointment we haven't won the game for sure," he said.
"The second leg is at Old Trafford and with our record there we must have a good chance to win the match and that's what we need to do, to win the match in front of own fans.
"We're capable of doing that, the game isn't finished but we've given ourselves a chance of doing that."